How to turn off the built-in flash of the A77 in remote control mode?

I would like to use the built-in flash of my A77 to control remote flashes, but not contribute at all to the lighting of the image. The image is taken using a mirror so the built-in flash will be visible and should not be emitting any light in the picture.

It is not possible, since codes in the light burst are used to trigger the distant flash(es).

But the best thing you can do is put a piece of black film (black part of a negative) over the built-in flash. It will dim most of the visible light, while allowing the needed infra-red light to pass and reach the external flash.

Thanks. The A55 could do it. I fact that's all it could do. It built-in flash could not be used for fill light because it would control the remote flash BEFORE the exposure. I was wondering if there is a setting to set that kind of behavior.

I would like to use the built-in flash of my A77 to control remote flashes, but not contribute at all to the lighting of the image. The image is taken using a mirror so the built-in flash will be visible and should not be emitting any light in the picture.

Is this possible? If yes, how?

Bart7D
wrote:

It is not possible, since codes in the light burst are used to trigger the distant flash(es)...

Yes, it is possible.

greves2
, I assume you are using a fully compatible remote flash that supports HSS. If so, shoot in S or M mode and make sure to set the shutter speed on the camera so that the 'HSS' indicator appears. On the A77 I think this will happen at 1/320s. Then the pop-up flash will never contribute any visible light to the scene.